In-cell touch panel and touch display device

ABSTRACT

An In-Cell touch panel is disclosed. The panel includes a color filter substrate, a common electrode disposed on the color filter substrate, and an array substrate disposed opposite to the color filter substrate. The panel also includes an Integrated Circuit disposed on the array substrate, a plurality of data lines on the array substrate, and a plurality of gate lines on the array substrate. The gate lines are perpendicular to the data lines, the common electrode is divided into a plurality of common electrode lines, the common electrode lines are configured to function as drive electrodes or sense electrodes, the IC is configured to perform a timesharing function for providing display signals and touch drive signals. In addition, the IC is also configured to detect touch signals.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims the benefit of priority to Chinese PatentApplication No. 201210484619.5, entitled, “In-Cell Touch panel And TouchDisplay Device”, filed with the Chinese Patent Office on Nov. 23, 2012,the contents of which is incorporated herein by reference in itsentirety.

TECHNICAL FIELD

The present invention relates to flat panel display technologies, and inparticularly to an In-Cell touch panel and a touch display device.

BACKGROUND OF THE INVENTION

Since a touch panel embedded in a liquid crystal display device can beintegrated with a color filter substrate (i.e. a color filter plate),the thickness of the whole touch display device is effectively reducedand the production process of the device is effectively simplified, thussuch a device has been widely used. Generally, drive lines and senselines used for a touch function are disposed at a side of the colorfilter substrate in an In-Cell touch panel, but it is difficult todisposed the drive lines and the sense lines used for the touch functionat the side of the color filter substrate in a liquid crystal displaydevice of a vertical drive electric field mode such as Twisted Nematic(TN), because a common electrode is disposed at the side of the colorfilter substrate. In order to achieve the built-in touch function of theliquid crystal display device of the TN mode, it has been proposed thatthe data lines and the gate lines at a side of an array substrate alsofunction as the drive lines and the sense lines of the touch panel.

As illustrated in FIG. 1, the In-Cell touch panel 100 includes an arraysubstrate 101, a color filter substrate 102, and a liquid crystal layer103 sandwiched between the array substrate 101 and the color filtersubstrate 102. A number of data lines and gate lines are disposed on thearray substrate 101, and the color filter substrate is connected with atimesharing Integrated Circuit (IC) 104. The data lines and the gatelines are respectively connected with the timesharing IC 104 through thecolor filter substrate 102. A frame scanning period of the timesharingIC 104 includes a touch period and a display period, the timesharing IC104 sends touch drive signals to the data lines and the gate lines, anddetects touch signals of the gate lines or the data lines at the sametime during the touch period; and the timesharing IC 104 sends displaysignals to the data lines or the gate lines during the display period.Thus, the timesharing IC 104 not only provides the touch drive signalsand the display signals, but also detects the touch signals, hence theload of the timesharing IC 104 is multiplied, and the timesharing IC 104is unable to support such rapidly increased load especially in the caseof a high resolution display device.

In addition, the data lines and the gate lines also function as thedrive lines and the sense lines used for the touch function in the abovetechnical solution, thus, for a mutual capacitor touch panel, the datalines and the gate lines are respectively used as plates for the mutualcapacitor. However, due to the limited line widths of the data lines andthe gate lines, the mutual capacitance of the touch panel caused by themis relatively small, and thus the sensitivity of the touch panel isseriously influenced.

In summary, the data lines and the gate lines also function as the drivelines and the sense lines of the In-Cell touch panel for the liquidcrystal display device of a vertical drive electric field, where theIn-Cell touch panel is demanding for the timesharing IC and causes therelatively small mutual capacitance of the touch panel, thus thedevelopment of such liquid crystal display device is seriouslyinfluenced.

BRIEF SUMMARY OF THE INVENTION

One inventive aspect is an In-Cell touch panel. The panel includes acolor filter substrate, a common electrode disposed on the color filtersubstrate, and an array substrate disposed opposite to the color filtersubstrate. The panel also includes an Integrated Circuit disposed on thearray substrate, a plurality of data lines on the array substrate, and aplurality of gate lines on the array substrate. The gate lines areperpendicular to the data lines, the common electrode is divided into aplurality of common electrode lines, the common electrode lines areconfigured to function as drive electrodes or sense electrodes, the ICis configured to perform a timesharing function for providing displaysignals and touch drive signals. In addition, the IC is also configuredto detect touch signals.

Another inventive aspect is a touch display device, including an In-Celltouch panel, including a color filter substrate, a common electrodedisposed on the color filter substrate, an array substrate disposedopposite to the color filter substrate, an Integrated Circuit (IC)disposed on the array substrate, a plurality of data lines on the arraysubstrate, and a plurality of gate lines on the array substrate, wherethe gate lines are perpendicular to the data lines, where, the commonelectrode is divided into a plurality of common electrode lines, wherethe common electrode lines are configured to function as driveelectrodes or sense electrodes, and where the IC is configured toperform a timesharing function for providing display signals and touchdrive signals, and where the IC is also configured to detect touchsignals, and a backlight module fixed to the In-Cell touch panel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view showing the structure of an In-Cell touchpanel in the prior art.

FIG. 2 is a schematic view showing the structure of an In-Cell touchpanel according to an embodiment of the invention.

FIG. 3 is a schematic top view of a color filter substrate according toan embodiment of the invention.

FIG. 4 is a schematic top view of an array substrate according to anembodiment of the invention.

FIG. 5 is a schematic view showing the formation of a touch mutualcapacitor according to an embodiment of the invention.

FIG. 6 is a schematic view showing the formation of a touch mutualcapacitor according to another embodiment of the invention.

FIG. 7 is a schematic view showing the structure of an In-Cell touchpanel according to still another embodiment of the invention.

FIG. 8 is a schematic view showing the structure of an In-Cell touchpanel according to still another embodiment of the invention.

FIG. 9 is a schematic view showing the structure of a touch displaydevice according to an embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The concept of the present invention is that the common electrodelocated on the color filter substrate is divided into a plurality ofcommon electrode lines, where the common electrode lines also functionas drive electrodes or sense electrodes, further, the IC located on thearray substrate is a timesharing IC, where the IC located on the arraysubstrate is used to provide the In-Cell touch panel with displaysignals and touch drive signals, and detect touch signals of the In-Celltouch panel. As for the In-Cell touch panel, the timesharing IC doesn'tprovide all the touch drive signals to the data lines or the gate linesalready withstand heavy loads and the data lines or the gate linesalready withstand heavy load do not provide all the touch detectingsignals during the touch period, instead, the touch drive signals or thetouch detecting signals is provided by the common electrode lineswithstand a relatively small load. Therefore, the load of thetimesharing IC can be reduced during the touch period, for the purposeof reducing the requirements for the load of the timesharing IC by theIn-Cell touch panel.

On the other hand, because the line width of the common electrode lineis larger than the line width of the data line or the gate line, theeffective relative area of a touch mutual capacitor formed by the abovecommon electrode line and the data line or the gate line is increased,so that the touch mutual capacitance is increased, thus the touchsensitivity can be improved.

Further detailed description will be made below in conjunction with theaccompanying drawings in order for better understanding on the object,solutions and advantages of the present invention.

As illustrated in FIG. 2, an In-Cell touch panel 200 of an embodiment ofthe present invention includes: a color filter substrate 201, an arraysubstrate 202, and a liquid crystal layer 203 disposed between the colorfilter substrate 201 and the array substrate 202, where the arraysubstrate 202 and the color filter substrate 201 are disposed oppositeto each other. A timesharing IC 204 is disposed on the array substrate202, and used for providing the In-Cell touch panel 200 with displaysignals and touch drive signals and detecting the touch signals of theIn-Cell touch panel 200.

A scanning period of the timesharing IC 204 includes a touch period anda displaying period; the timesharing IC 204 provides the In-Cell touchpanel 200 with the touch drive signals and detects the touch signal ofthe In-Cell touch panel 200 at the same time during the touch period;also, the timesharing IC 204 provides the embedded touch panel 200 withthe display drive signals during the displaying period.

As illustrated in FIG. 3 in combination with FIG. 2, a common electrode205 is divided into a plurality of common electrode lines 2051, 2053, .. . , 205n, where the common electrode 205 is disposed on the colorfilter substrate 201. The common electrode lines 2051, 2052, . . . ,205n function as drive electrodes or sense electrodes during the touchperiod of the timesharing IC 204.

As illustrated in FIG. 4, multiple data lines 206 and multiple gatelines 207 disposed perpendicular to the data lines 206 are formed on thearray substrate 202. Multiple data lines 206 or multiple gate lines 207function as sense electrodes or drive electrodes during the touch periodof the timesharing IC 204.

In the present embodiment, as illustrated in FIG. 5, the data lines 206function as the sense electrodes or drive electrodes, and the commonelectrode lines 2051, 2052, . . . , 205n are disposed perpendicular tothe data lines 206. The common electrode lines 2051, 2052, . . . , 205 nfunction as the drive electrodes when the data lines 206 function as thesense electrodes, and the common electrode lines 2051, 2052, . . . ,205n function as the sense electrodes when the data lines 206 functionas the drive electrodes. In other words, two plates of the touch mutualcapacitor are respectively the data lines 206 and the common electrodelines 2051, 2052, . . . , 205n. It should be noted for FIG. 5 that thegate lines 207, the color filter substrate 201 and other elements arenot shown in FIG. 5 in order to clearly show the relationships of thedata lines 206 and common electrode lines 2051, 2052, . . . , 205n.

Alternatively, the gate lines 207 can also function as a plate of thetouch mutual capacitor. In another embodiment of the present invention,as illustrated in FIG. 6, the gate lines 207 serve as sense electrodesor drive electrodes, and the common electrode lines 2051, 2052, . . . ,205n are disposed perpendicular to the gate lines 207. The commonelectrode lines 2051, 2052, . . . , 205n serve as the drive electrodeswhen the gate lines 207 function as the sense electrodes;

and the common electrode lines 2051, 2052, . . . , 205n function as thesense electrodes when the gate lines 207 function as the driveelectrodes. In other words, two plates of the touch mutual capacitor arerespectively the gate lines 207 and the common electrode lines 2051,2052, . . . , 205n. It should be noted for FIG. 6 that the data lines206, the color filter substrate 201 and other elements are not shown inFIG. 6 in order to clearly show the relationships of the gate lines 207and the common electrode lines 2051, 2052, . . . , 205n.

In summary, because the plurality of common electrode lines 2051, 2052,. . . , 205n function as a plate of the touch mutual capacitor, thetouch drive signals or the touch signals of the timesharing IC 204 isprovided by the plurality of common electrode lines 2051, 2052, . . . ,205n withstand relatively small loads during the touch period, thuseffectively reducing the load of the timesharing IC 204.

As illustrated in FIGS. 5 and 6, the common electrode 205 is dividedinto the plurality of common electrode lines 2051, 2052, . . . , 205n,it is possible that the line widths of the common electrode lines 2051,2052, . . . , 205n are larger than those of the data lines 206 or thegate lines 207. Preferably, the range of the line widths of the commonelectrode lines 2051, 2052, . . . , 205n is 3 mm˜5 mm.

On the array substrate 202, the plurality of data lines 206 intersectwith the plurality of gate lines 207 to define a plurality of pixels inan array, and the pixels are divided into multiple pixel rows andmultiple pixel columns. After the common electrode 205 is divided intomultiple common electrode lines 2051, 2052, . . . , 205n, the variouspixel rows or columns may be charged inconsistently. In order to avoiduneven display caused by the inconsistent charging, the plurality ofcommon electrode lines 2051, 2052, . . . , 205n can be disposed tooverlap with the plurality of pixel rows or columns. Preferably, thewidth of each of the plurality of common electrode lines 2051, 2052, . .. , 205n is equal to the width of the pixel row or column, in this case,the In-Cell touch panel can be driven in a row/column inversion drivingmode, or the shift register circuit of the array substrate may beselectively used to transfer signals for the color filter substrate, sothat the driving designs can be selected more widely and be moreflexible.

As illustrated in FIG. 2, two plates of the touch mutual capacitor arethe common electrode lines 2051, 2052, . . . , 205n and the data lines206 or the gate lines 207, and a dielectric layer between the two platesof the touch mutual capacitor includes the liquid crystal layer 203. Inthe liquid crystal display device with a vertical drive electric field,the angles between the liquid crystal molecules and the color filtersubstrate 201 or the array substrate 202 vary with the drive voltages.Because the liquid crystal molecules are polar molecules, when theangles between the liquid crystal molecules and the color filtersubstrate 201 are changed, means that the dielectric constant of thedielectric layer between the two plates of the touch mutual capacitor ischanged, so that the touch mutual capacitance per se is changed.However, such change of the touch mutual capacitance is not caused bythe external touch and thus is not a real touch signal, therefore, suchchange of the touch mutual capacitance caused by the rotation of theliquid crystal molecules is noise for the timesharing IC 204 used fordetecting the touch signals.

In order to reduce the above noise caused by the rotation of the liquidcrystal molecules, a layer of organic film is added between the twoplates of the touch mutual capacitor, that is, the dielectric layer ofthe touch mutual capacitor includes the liquid crystal layer 203 and theorganic film, to alleviate the variation of the dielectric constant ofthe whole dielectric layer caused by the rotation of the liquid crystalmolecules. Specifically, an organic film made of acrylic copolymer resinis disposed on the color filter substrate 201 or the array substrate202.

More specifically, as illustrated in FIG. 7, on the array substrate 202,further comprises a protect layer 209 disposed on the data lines 206, aswell as a pixel electrode layer 210 disposed above the protect layer209. An organic film layer 211 having a thickness of a range of 1 μm˜3μm is disposed between the protect layer 209 and the pixel electrodelayer 210. Of course, the organic film 211 can be alternatively disposedon a side of the common electrode 205, where the side is toward thearray substrate 202(not shown).

Of course, in still another embodiment of the present invention, inorder to effectively reduce the variation of the dielectric constant ofthe whole dielectric layer caused by the rotation of the liquid crystalmolecules, as illustrated in FIG. 8, an organic film is disposed on eachof the color filter substrate 201 and the array substrate 202. Inparticular, a first organic film 212 is disposed between the protectlayer 209 and the pixel electrode layer 210, and a second organic film213 is disposed on a side of the common electrode 205, where the side istoward the array substrate 202. Preferably, the thicknesses of the firstorganic film 212 and the second organic film 213 are in a range of 0.5μm˜1.5 μm.

Accordingly, as illustrated in FIG. 9, the present invention furthercomprises a touch display device 300 including the In-Cell touch panel200 and a backlight module 400, while the In-Cell touch panel 200 isfixed in the backlight module 400. To assemble the touch display device300, the array substrate 202 is disposed to face a user, while the colorfilter substrate 201 is disposed to face the backlight module 400, sothat when the user touches the In-Cell touch panel 200, the user iscloser to the touch mutual capacitor to improve the touch sensitivity.

In summary, the common electrode on the color filter substrate isdivided into a plurality of common electrode lines, and the commonelectrode lines also function as the drive electrodes or the senseelectrodes. As for the above In-Cell touch panel, during the touchperiod of the timesharing IC, not all of the touch drive signals areprovided to the data lines or the gate lines, where the data lines orthe gate lines already withstand very heavy loads, and not all of thetouch detecting signals are provided by the gate lines and the datalines already withstand the very heavy loads, and one of the touch drivesignals or the touch detecting signals is provided by the commonelectrode lines withstand a less load. Accordingly, the load of thetimesharing IC during the touch period can be reduced for the purpose ofreducing the requirements for the load of the timesharing IC by theIn-Cell touch panel.

On the other hand, the line width of the common electrode line is largerthan the line width of the gate line or the gate line, so that theeffective relative area of the touch mutual capacitor formed by theabove common electrode line and the data lines or the gate lines isincreased to increase the touch mutual capacitance, and hence to improvethe touch sensitivity. Meanwhile, an organic film is added between twoplates of the touch mutual capacitor to reduce the influence on thedielectric constant of the whole medium layer caused by the rotation ofthe liquid crystal molecules, to further improve the touch sensitivity.

Apparently, the skilled in the art can make various changes andmodifications to the present invention without departing from the spiritand scope of the present invention. Therefore, if the changes and themodifications on the present invention are within the scope of theclaims and their equivalent technologies, the present invention areintend to include these changes and modifications.

What is claimed is:
 1. An In-Cell touch panel, comprising: an arraysubstrate; a color filter substrate placed opposite to the arraysubstrate; a layer of liquid crystals disposed in between thesubstrates; wherein the color filter substrate comprises a plurality ofcommon electrode lines disposed on the surface facing the arraysubstrate, configured to function as drive electrodes or senseelectrodes; wherein the array substrate comprises a display area and aperiphery area, wherein a plurality of data lines and a plurality ofgate lines are disposed in the display area on the array substratesurface facing the color filter substrate, wherein the gate lines areperpendicular to the data lines; wherein a protect layer is formeddirectly on the plurality of data lines and an organic film layer isformed on the protect layer, and a pixel layer is formed on the organicfilm layer; and an Integrated Circuit (IC) disposed on the peripheryarea of the array substrate, wherein the IC is configured to perform atimesharing function for providing display signals and touch drivesignals, and wherein the IC is also configured to detect touch signals,and wherein a scanning period of the IC includes a touch period and adisplay period, wherein during the touch period, the IC provides thetouch drive signals and detects the touch signals, and wherein the ICprovides the display drive signals during the display period.
 2. TheIn-Cell touch panel according to claim 1, wherein the line width of eachof the common electrode lines is between about 3 mm and about 5 mm. 3.The In-Cell touch panel according to claim 1, wherein the line width ofeach of the common electrode lines is equal to the width of the pixelrow or pixel column.
 4. The In-Cell touch panel according to claim 1,further comprising: a pixel electrode layer formed above the protectlayer, wherein the organic film comprises an acrylic copolymer resin. 5.The In-Cell touch panel according to claim 4, wherein the organic filmis formed between the protect layer and the pixel electrode layer. 6.The In-Cell touch panel according to claim 1, wherein the line width ofthe common electrode lines is greater than a line width of the datalines.
 7. The In-Cell touch panel according to claim 1, wherein the linewidth of the common electrode lines is greater than a line width of thegate lines.
 8. The In-Cell touch panel according to claim 1, wherein thearray substrate further comprises a plurality of pixel rows and aplurality of pixel columns connected to the data lines and to the gatelines, and wherein the common electrode lines overlap the pixel rows oroverlap the pixel columns.
 9. A touch display device, comprising: anIn-Cell touch panel and a backlight module fixed to the In-Cell touchpanel, wherein the In-Cell touch panel comprises: an array substrate; acolor filter substrate placed opposite to the array substrate; a layerof liquid crystals disposed in between the substrates; wherein the colorfilter substrate comprises a plurality of common electrode linesdisposed on the surface facing the array substrate, configured tofunction as drive electrodes or sense electrodes; wherein the arraysubstrate comprises a display area and a periphery area, wherein aplurality of data lines and a plurality of gate lines are disposed inthe display area on the array substrate surface facing the color filtersubstrate, wherein the gate lines are perpendicular to the data lines;wherein a protect layer is formed directly on the plurality of datalines and an organic film layer is formed on the protect layer, and apixel layer is formed on the organic film layer; and an IntegratedCircuit (IC) disposed on the periphery area of the array substrate,wherein the IC is configured to perform a timesharing function forproviding display signals and touch drive signals, and wherein the IC isalso configured to detect touch signals, and wherein a scanning periodof the IC includes a touch period and a display period, wherein duringthe touch period, the IC provides the touch drive signals and detectsthe touch signals, and wherein the IC provides the display drive signalsduring the display period.
 10. The touch display device according toclaim 9, wherein the color filter substrate faces the backlight moduleand the array substrate faces a user.